1. Field of the Invention
The present invention is directed to a mass damper system with a damper mass carrier at which is received at least one damper mass, which is movable relative to the damper mass carrier, and at least one stop. The damper mass moves within a predetermined movement region at least during an operating state in which a rotational movement of the damper mass carrier around a central axis has exceeded a predetermined limit speed.
2. Detailed Description of Prior Art
A mass damper system is known from DE 10 2009 042 818 A1. According to FIG. 1 of DE 10 2009 042 818A1, this mass damper system has in the radially inner region an annular component part which, like a hub disk serving as damper mass carrier, is secured to an output-side flywheel mass of the mass damper system. As can be seen particularly in FIG. 5 of DE 10 2009 042 818A21, the hub disk serves to receive a plurality of damper masses arranged successively in circumferential direction and, to this end, has two guide paths for each damper mass, these two guide paths being connected in each instance to two guide paths of the respective damper mass via a rolling body. The damper masses are displaceable in each instance in circumferential direction relative to the hub disk until coming in contact by radial extensions with a flexible stop associated with the respective movement direction. According to the construction in FIG. 1 of DE 10 2009 042 818A1, the flexible stop is provided at the annular component part.
In driving operation, i.e., in an operating state in which the rotational movement of the mass damper system—and, therefore, of the damper mass carrier—around a central axis has exceeded a predetermined limit speed, the damper masses remain inside a movement region bounded at one end by an initial position in which the damper masses are free from a deflection in circumferential direction and, at the other end, by a limit position in which the damper masses have undergone a deflection of a predetermined deflection distance in circumferential direction. While the damper masses operate sufficiently noiselessly in driving mode, the rotational movement of the mass damper system and, therefore, of the damper mass carrier around the central axis drops below the predetermined limit speed in other operating states, e.g., when turning off the corresponding drive such as an internal combustion engine, or in creep mode of the corresponding vehicle, and the centrifugal force acting on the damper masses accordingly decreases. As soon as the centrifugal force has dropped below the weight force, the damper masses drop down and generate an unacceptable impact noise in their paths and/or at the stops.
In a mass damper system with a damper mass carrier known from DE 10 2010 054 207 A1, there are damper masses provided on the damper mass carrier which have, according to FIGS. 4 and 5, circumferential projections at the radial outer regions thereof on the circumferential side. While increasing the weight of the damper masses, their inertial behavior can be enhanced in a particularly efficient manner by this step. In order to accommodate the same quantity of damper masses at the damper mass carrier without appreciably affecting the maximum oscillating angle of the damper masses in spite of the resulting greater extension of the damper masses in circumferential direction, the circumferential projections of the damper masses are formed with a curved contour. When the damper masses are adjacent to one another in circumferential direction, this contour fosters a radial overlapping in that it causes the circumferential projections to slide one upon the other when the damper masses approach one another. A relative swiveling position of the two damper masses, which already existed before, is enhanced in this way. While the efficiency of the damper masses in driving mode is improved as a result of this constructional step, this step has no effect in the other operating states mentioned above. For this reason, a stop provided at the damper mass carrier that arrests the movement of the associated damper mass in direction of the stop is associated with every damper mass in each circumferential deflecting direction. The damper masses come in contact with the respective associated stop with their circumferential sides and radially overlap the stop with their circumferential projections.
Understandably, the severity of the impact noise when the damper mass encounters the stop are proportionate to the acceleration of the damper mass leading up to the impact. Diverse measures have been undertaken to damp this impact noise, for example, forming the stop with an elastically deformable surface. However, it must be assumed that the cross section of the stop is enlarged as a result of forming the surface in this way, which would in turn have a disadvantageous effect on the maximum swiveling angle of the damper masses.